Mic McPhearson, a good friend of mine, who has forgot more about ballistics than most people will ever know, told me that small primer .45 ACP can be more consistent than large primers. In our game, I do not think it would make a difference.

Hello Blackfoot. I've tested that using Green Dot powder and 200 gr RNFP bullets. Everything the same except the primers. My data says Garrison Joe is just about right - plus 25 fps for the large primer. I know some report better consistency with the small primers. However, my data did not show a significant difference in extreme spread or standard deviation between the two.